Portable power-driven file



Jan. 3, 1950 F. A. COLE PORTABLE POWER-DRIVER FILE Filed Dec.- 3, 1946 E:m J 6 4 JT a am 90. \5

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Patented Jan. 3, 1950 UNITED STATES PATENT OFFICE Claims.

This invention relates to a metal-surfacing apparatus in the nature of afile or smoother and, in particular, to a portable device having adriving motor associated therewith.

It is frequently desirable in the metal-working arts to smooth thesurface of a member after it has been worked on. Hand ling is commonlyresorted to for this purpose but it is a slow and costly operation andis characterized by lack of I have invented a portable power-driven toolcapable of smoothing metal surfaces uniformly and rapidly, which ispractically as simple to operate as an ordinary file but is capable ofperforming a surfacing operation much more efficiently andsatisfactorily. In a preferred embodiment of the invention, anopen-bottomed housing is provided with a horizontal cross wall above thebottom thereof sloping downwardly at each end forming gudeways. A yokeis slidable along each guideway. A plurality of toothed blades extendbetween the yokes, each blade being secured to one yoke and slidable onthe other, the toothed edges of the blades being exposed at the openbottom of the housing. A shaft is journaled in the housing and isadapted to be driven by a motor mounted thereon. Barrel cams on theshaft cause reciprocation of the yokes and blades on rotation of theshaft. Lifter plates extend along the blades and are mounted forvertical movement relative to the housing whereby to lift the apparatuson the retraction stroke of the blades, Disc cams on the shaft causereciprocation of the lifter plates in timed relation to thereciprocation of the toothed blades.

A complete understanding of the invention may be obtained from thefollowing detailed description and explanation referring to theaccompanying drawings for the purpose ofillustration. In the drawings,

Figure 1 is a vertical longitudinal section through the apparatusshowing parts in elevation;

Figure 2 is a bottom plan view with parts broken away and parts omittedfor the sake of clearness; and

Figures 3 and 4 are transverse sections on the planes of lines IlI--IIIand IV-IV, respectively, of Figure 1 looking in opposite directions.

Referring in detail to the drawings, an openbottomed housing I0rectangular in plan has side walls II, end walls I2 and top I3. A crosswall I4 extending between the ends and sides is located intermediate thebottom and top of the housing and is secured therein in any convenientmanner as by welding. The end portions of the wall are plane and slopedownwardly forming guideways I5. Yokes I6 and I'I are slidable along theunder surface of the guideways.

A plurality of toothed blades I8 extend between the yokes I6 and I1.Alternate blades are secured to one yoke and slidable on the other. Eachblade has holes at one end for bolts I9 inserted through the spaceddepending sides of yoke Il and a slot at the other end for sliding onsimilar bolts on the yoke I6, or vice versa. The teeth on alternateblades are oppositely directed so that a cutting stroke is effected whenthe blades are pulled toward the ends of the housing A shaft 20 isjournaled longitudinally of the housing I0 in bearings 2| in the ends ofthe housing and bearings 22 on the Wall I4. The shaft is driven by amotor 23 which may conveniently be mounted on the top I3 of the housing.A worm 24 on the motor shaft meshes with a worrnwheel 25 on the shaft 20between the bearings '22. Frusto-conical barrel cams 2B are secured tothe shaft 2E) for reciprocating the yokes I6 and I'I. Each cam has acircumferential slot 21 adapted to accommodate the ball head of anactuator 28 extending upwardly from one of the yokes through a slot 29in the sloping end portion or guideway of the wall I4. It will beapparent that, by reason of the slope of the guideways, the blades willbe forced downwardly as they are moved toward the ends of the housing.The tool, being bodily manipulated by hand, is free to rise, of course,as the blades advance but the reaction of the weight of the tool urgesthe blades against the work. To facilitate manipulating the tool, themotor 23 may conveniently be mounted in a bracket 30 having a hand grip3l provided with a trigger switch 32 for controlling the motor.

In order to raise the tool and the toothed edges of the blades I8 fromthe surface being worked on as the blades are retracted, i. e., pushedtoward the center of the housing, I provide a plurality of lifter plates33 extending alongside the toothed blades and between adjacent blades.The plates 33 are secured at their upper edges to a horizontal plate 34.The lower edges of the plates 33 are adapted to bear on the surface ofthe work. Guide pins 35 extend upwardly from the plate 34 throughbearings 3B in the wall I4. The pins 35 are urged against disc cams 31on the shaft 20 by compression springs 38 surrounding the bearings forthe guide pins and engaging flanges 39 thereon. The springs 38 urge thenon-creeping.

plates 33 and 34 upwardly at all times. The cams 31 are so shaped andpositioned on the shaft 20 as to move the plates 33 and 34 downwardlywhile the yokes I6 and I1 are being moved inwardly to retract the bladesto a position for starting a cutting stroke. When the blades havereached this position, the cam permits the springs 38 to raise theplates 33 and 34, thereby lowering the housing so that the toothed edgesof the blades engage the work. It will thus be apparent that the housingl vibrates vertically during the operation of the device.

Certain of the blades I8, specifically those designated |8a, extendbeyond the ends of the other blades and outwardly through a slot 40 inone end of the housing. The projecting portions of these blades may beused in the manner of a saw for rough cutting or ripping operations.

It will be apparent that the invention lprovides a portable power-drivenmachine for smoothing .metal surf aces which is characterizedy bynumerous advantages. In the `:first place, the apparatus 3 is relativelysimple and inexpensive to manufacture. .Its .'use,v furthermoregdoes notrequire any special skill. The actionof the cutting blades is quickandaccurate. All moving parts'are enclosed except the toothed edges of theblades.

Sinceialternate'z blades are reciprocated in opposite'directions'andvthus'have their teeth facing in opposite directions, thexdevice as awhole'is The dust vand chips resulting from the smoothing operation arefed out freely because. the cutting'blades are lifted clear o-f the.workfon the retraction stroke. On the cutting stroke, the weight of thetool, as explained above, serves'fto apply the necessary workingpressure to the blades.

Although I have illustrated-.and described only a preferred embodimentofthe invention, it will be recognizedthat changesin the constructiondisclosed may be'made'without departing .from

`the spiritiof the 'invention or the scope of the appended claims.Instead of using individual -cutting blades vassembled in twocooperating groups, the individual blades of which are interleaved, theblades of eachgroup may be formed Yby slotting a block; the `block beingsecured .to one of the yokes. Instead ofmounting the driving motoren thehousing, furthermore, I may drive the shaftil throughr a flexible shaft'from :alternate ones of said blades' having. their respective teethdirected in opposite directions, all

f of said-blades having their respective teeth directed in one directioncomprising one group and all of the remaining of `said blades comprisinganother group, a yoke attached tov each -of said groups of said bladeshaving their teeth respecf tively directed in the same direction, meansfor ymoving said yokes apart substantially parallel Ito the length ofsaid blades to effect a simultanemous lineal' cutting stroke in oppositedirections, Y whereby said portable powerdriven' fileV is sub--fstantially non-creeping during' operation.

2. In a portable power-driven lile for smoothing metal surfaces or thelike, in combination, a plurality of toothed blades in parallelarrangement adapted to form a substantially planar toothed filingsurface, alternate ones of said blades having their teeth oppositely andrespectively directed axially thereof, a yoke attached to each group ofsaid blades having their teeth directed in the same direction, means formoving said yokes `apart substantially parallel to said toothed surfaceand to the longitudinal axes of said blades to effect a simultaneouscutting stroke .n opposite directions, said means for moving `be ingfurther adapted to move said yokes toward each other to effect asimultaneous linear retraction stroke of said blades, an independentlifting Vsurface-for said yokes, and means for extending said liftingsurface while said yokes are vbeing so moved toward each other, wherebyall of said blades are maintained in relatively sharp condition bybeing'kept out of contact with said metal surfacesorthe like'duringsaidretraction stroke.

3. In a portablepower-.driven ille for'smoothing metal surfaces and thellike,.in combination, a plurality of toothed'bladesfset on edge inparallel arrangement and adapted to form asubstantially planarv toothed:ling surface, adjoining blades of said plurality having their teethoppositely directed along the longitudinal axes of said respectiveblades, a yoke attached toeachgroup of said blades .having their.teethidirected in the same direction, each said yoke having slidingengagement with the group of said blades having f 'their teeth directedin the opposite direction, said toward each other at the same ratesubstantially parallel to said toothed surface and to said longitudinalaxesrofsaid blades to effect a simultaneous linear retraction stroke ofsaid blades, whereby simultaneous respective cutting and retractionmovement of all blades occurs in linear opposed equal force fashion toprevent creeping forces during operation, each of said blades beingsupportably engaged by said yokes at spaced 1 points along the lengththereof.

4. In a portable power-driven le for smooth- :ing metal surfaces or thelike, in combination, a plurality of toothed bladesset on edge inparallel arrangement and adapted to. form Va substantially planartoothed vfiling surface, vadjoining blades of said plurality havingtheir teeth oppositely directed. along .the longitudinal axes of saidrespective blades, a yoke attached to each group of said blades havingtheir teeth directed in the same direction, each said yoke-havingsliding engagement with thegrOllP 0f Said-blades having their teethdirected in the-opposite direction, means for simultaneously movingsaid-yokes apart at the same rate substantially parallel lto saidtoothed. surface and to said longitudinal axes of said blades to effecta simultaneous linear cutting stroke in oppositefdirectionsagainst said:metal surfaces or the like, means for simultaneously moving said yokestoward each other at i the same rate substantially parallel I'to 'i saidtoothed surface and-toV said longitudinal axes of said blades to effecta simultaneous linear retraction stroke of said blades, lifting platespositioned on edge between said blades and adapted to be reciprocatedvertically, means for moving said lifting plates against said metalsurfaces or the like during said linear retraction stroke of said bladesto lift said blades off of said metal surfaces or the like duringretraction, whereby said portable power-driven iile is substantiallynon-creeping during operation and said yokes maintain said blades inplanar relation to said metal surfaces or the like.

5. In a portable power-driven le for smoothing metal surfaces or thelike, in combination, a plurality of toothed blades set on edge inparallel arrangement and adapted to form a substantially planar toothedfiling surface, adjoining blades of said plurality having their teethoppositely directed along the longitudinal axes of said respectiveblades, a yoke attached to each group of said blades having their teethdirected in the same direction, each said yoke having slotted engagementwith the group of said blades having their teeth directed in theopposite direction, said slotted engagement being spaced from the pointof attachment between said group and its respective yoke, cams forsimultaneously moving said yokes apart at the same rate substantiallyparallel to said toothed surface and to said longitudinal axes of saidblades to effect a simultaneous linear cutting stroke in oppositedirections against said metal surfaces or the like, downwardly andoutwardly sloping guideways for said yokes adapted to move said bladestoward said metal surfaces or the like during said cutting stroke, saidcams being further adapted to simultaneously move said yokes toward eachother at the same rate substantially parallel to said toothed surfaceand to said longitudinal axes of said blades to eifect a simultaneouslinear retraction stroke of said blades in opposite directions, liftingplates positioned on edge between said blades and adapted to bereciprocated vertically, cam means for moving said lifting platesagainst said metal surfaces and the like during said linear retractionstroke of said blades to lift said blades away from said metal surfacesand the like during retraction, whereby said portable power-driven le issubstantially non-creeping during operation and said blades aremaintained in relatively sharp condition by being lifted during saidretraction stroke.

FRANK A. COLE.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,025,754 Little May 7, 19121,437,190 Oxley Nov. 28, 1922 1,856,887 Scheppy May 3, 1932 1,871,020Wyzenbeek Aug. 9, 1932 1,993,797 Peterson Mar. 12, 1935 2,103,444 BauchDec. 28, 1937 2,123,426 Kehle July l2, 1938 FOREIGN PATENTS NumberCountry Date 560,035 France June 28, 1923

